Cholesterol biosynthesis
(R-HSA-191273)

Species Homo sapiens

Summation

Cholesterol is synthesized de novo from from acetyl CoA. The overall synthetic process is outlined in the figure below. Enzymes whose regulation plays a major role in determining the rate of cholesterol synthesis in the body are highlighted in red, and connections to other metabolic processes are indicated. The transformation of lanosterol into cholesterol requires multiple steps, including the removal of three methyl groups, the reduction of one double bond and the migration of another. These reactions may not occur in a single fixed order in the body, so the linear pathway laid out here following the work of Gaylor and colleagues (Gaylor 2002) is an oversimplification of the process that occurs in vivo. Defects in several of the enzymes involved in this process are associated with human disease and have provided useful insights into the regulatory roles of cholesterol and its synthetic intermediates in human development (Herman 2003; Song et al. 2005).